The DUP who prop up British Prime Minister Theresa May’s government sent her a stark warning over her draft Brexit divorce deal, pulling support in several parliamentary votes on a finance bill.

The move breaches the DUP’s deal with May and throws further doubt over whether she has the numbers to approve a draft Brexit deal in parliament.

Since striking a draft divorce deal with the EU a week ago, some lawmakers in her Conservative Party have tried to trigger a leadership challenge and her Northern Irish allies have said the deal threatens the unity of the United Kingdom.

May vowed to fight on and has repeatedly cautioned her critics that if they topple her, the United Kingdom will be thrust into a potentially disorderly departure from the EU on March 29 or that Brexit could be put off or cancelled.

But in an ominous sign for her Brexit deal, which must be approved by the British parliament, the Democratic Unionist Party (DUP) failed to back her minority government in several votes on a finance bill on Monday.